I can't peg down my DS8 more than HG+, but the concepts are similar. I think modern management philosophy is more useful than parenting methodologies when dealing with a really smart kid. You aren't going to manipulate, scream, threaten, time out them into compliance. Trust, positive feedback loops, open communication, etc.
If you make it a game about your ego, they will play that game, too, enjoy it, and win often enough. Positive modeling is always relevant.
When DS was less tractable and wanted a debate for everything, then we will go through phases where he needs to debate for basics like what food is available, what gets watched on TV, whether we go anywhere on the weekend, etc. We've also learned to lowball options, because he'll want to debate for more.
Though posted a few times, I found the biggest influence with DS has been undivided attention. He wants that, and knows that if he makes a day awkward, then he loses out on that. With a guaranteed playtime each night that is all about what he wants to do, it is a useful bargaining chip.
